1. Field on the Invention
The present invention relates to an improvement to the ski binding described in U.S. application Ser. No. 579,376, filed Feb. 13, 1983, now U.S. Pat. No. 4,639,011, issued Jan. 27, 1987, and in French Patent Application No. 83 02309. In addition, the present invention relates to a ski provided with such a binding.
2. Description of Relevant Information
The U.S. and French applications referred to above relate to a safety binding or "front abutment" binding which comprises:
a jaw adapted to receive and to retain the front end of the ski boot with respect to the ski. Two lateral wings are provided for this purpose at the front of the jaw. The wings are adapted to grip the boot on both lateral sides thereof; PA1 a support element defining for the jaw, two rearwardly directed lines of support with respect to the ski, for guiding the lateral pivoting of the jaw. The two lines of support converge downwardly to a point, and define a common plane transverse with respect to the ski such that lateral pivoting of the jaw with respect to the ski, around either one of the support lines is accompanied by a lifting of the wings of the jaw with respect to the ski; and PA1 an elastic energization mechanism which presses the jaw rearwardly against the support element and biases the jaw elastically against lateral pivoting.
In the above-mentioned U.S. and French applications and in the description of the bindings discussed below, absent specific mention to the contrary, the relative positions of the various elements of the ski binding extend in the normal direction of displacement thereof.
This known binding is adapted to retain the front end of the boot on the ski, while the rear end is retained on the ski by other means. This front abutment is adapted to free the boot in response to excessive torsional forces at the level of the leg. When such torsional forces occur, they are also applied laterally to the wings of the binding, thereby overcoming the bias of the elastic energization system so as to laterally pivot the jaw and free the boot. An appropriate calibration system is provided for the elastic energization mechanism which makes it possible to adjust the release threshold above which the boot is released.
Such a simple system responds in an entirely satisfactory fashion to a fall which induces torsional movement of the boot. In such an instance, lateral pivoting of the jaw frees the boot due to the lateral pivoting of the retention wings. In addition, lateral pivoting of the jaw can also be accompanied by a frontward movement of the jaw with respect to the support element, against the resistance of the elastic energization mechanism.
However, it has been discovered that such a binding requires an additional complementary apparatus when a torsional fall is combined with a frontward fall.
During a frontward fall, the zone of the sole which is perpendicular to the front of the foot is applied against the ski with a substantial force directed downwardly, which serves to create an appreciable frictional force between the bottom of the sole and the ski. This frictional force opposes lateral pivoting of the boot, and its liberation from the jaw.